The so-called RL special edition glitch (name coined by Tumblr user @furbytech [1]) is a Furby bug observed in some 1998 Furbys having the RL factory code, where a Furby might produce glitched audio and freeze randomly. It is sometimes also referred to as “Shake n’ Bake”
Despite the name, it has also been noticed in non-special-edition Furbys too.[2][3]